interp: add wasip1 to known os list

Adds wasip1 to known OS list, introduced in golang/go#58141. Without this change, yaegi extract may fail.

Author: dennwc

interp/build.go

@@ -182,6 +182,7 @@ var knownOs = map[string]bool{
 	"openbsd":   true,
 	"plan9":     true,
 	"solaris":   true,
+	"wasip1":    true,
 	"windows":   true,
 }